Is there a difference between Admin and another author?

I’m having trouble trying to edit a website that was created with WP (I did not build it). I was given the login information, but I noticed that while on the dashboard, when I was browsing through the content that was published that the author was either the username I had been given or another name that simply said “admin.” Is there a difference between these two? Does the “admin” author have more editing privileges than a regular user on the site? If so, how can I log into the page so that I have an admin’s access to edit content?